Plating apparatus for plating a wafer

Abstract

The present invention provides for a plating apparatus and a method of plating, which improve the uniformity of a plated coating thickness without changing the flow velocity of a feed plating solution. An aperture can be provided at a center of a meshed anode electrode of the plating apparatus to obtain an electric field density distribution between the meshed anode electrode and a wafer that is lower in the central portion of the wafer than in the edge portion of the wafer.

What is claimed is: 
     
       1. A plating apparatus comprising: a plating tank suitable for holding a wafer so that a plating surface of the wafer faces upward;   plating solution supply means for causing a plating solution supplied to the plating surface of the wafer to flow from a center of the plating surface of the wafer toward a periphery of the plating surface of the wafer; and   an annular mesh anode electrode having a central aperture and a plurality of openings surrounding the central aperture, the annular anode electrode being disposed opposite the wafer for generating an electric field between said anode electrode and the wafer, using the wafer as a cathode, the electric field having a lower density in a central portion of the wafer than at an edge of the wafer.   
     
     
       2. The plating apparatus according to claim 1, wherein the wafer has a diameter and the anode electrode comprises a circular electrode having an outside diameter nearly equal to the diameter of the wafer. 
     
     
       3. The plating apparatus according to claim 1, wherein the wafer has a diameter and the aperture of the anode electrode comprises a circular aperture having a diameter of 40 to 80% of the diameter of the wafer. 
     
     
       4. The plating apparatus according to claim 1, wherein the mesh is plated with Ti/Pt. 
     
     
       5. The plating apparatus according to claim 1, wherein the anode electrode comprises a plate containing the central aperture and the openings and through which the plating solution can be supplied. 
     
     
       6. The plating apparatus according to claim 5, wherein the plate comprises Ta cladded with Pt.